4,604 research outputs found
The H.E.S.S. central data acquisition system
The High Energy Stereoscopic System (H.E.S.S.) is a system of Imaging
Atmospheric Cherenkov Telescopes (IACTs) located in the Khomas Highland in
Namibia. It measures cosmic gamma rays of very high energies (VHE; >100 GeV)
using the Earth's atmosphere as a calorimeter. The H.E.S.S. Array entered Phase
II in September 2012 with the inauguration of a fifth telescope that is larger
and more complex than the other four. This paper will give an overview of the
current H.E.S.S. central data acquisition (DAQ) system with particular emphasis
on the upgrades made to integrate the fifth telescope into the array. At first,
the various requirements for the central DAQ are discussed then the general
design principles employed to fulfil these requirements are described. Finally,
the performance, stability and reliability of the H.E.S.S. central DAQ are
presented. One of the major accomplishments is that less than 0.8% of
observation time has been lost due to central DAQ problems since 2009.Comment: 17 pages, 8 figures, published in Astroparticle Physic
Collisions of particles in locally AdS spacetimes I. Local description and global examples
We investigate 3-dimensional globally hyperbolic AdS manifolds containing
"particles", i.e., cone singularities along a graph . We impose
physically relevant conditions on the cone singularities, e.g. positivity of
mass (angle less than on time-like singular segments). We construct
examples of such manifolds, describe the cone singularities that can arise and
the way they can interact (the local geometry near the vertices of ).
We then adapt to this setting some notions like global hyperbolicity which are
natural for Lorentz manifolds, and construct some examples of globally
hyperbolic AdS manifolds with interacting particles.Comment: This is a rewritten version of the first part of arxiv:0905.1823.
That preprint was too long and contained two types of results, so we sliced
it in two. This is the first part. Some sections have been completely
rewritten so as to be more readable, at the cost of slightly less general
statements. Others parts have been notably improved to increase readabilit
Design thinking and sport for development: enhancing organizational innovation
© 2019, © 2019 Informa UK Limited, trading as Taylor & Francis Group. Rationale/purpose: To determine if the field of sport for development (SFD) presents opportunities for the employment of design thinking approaches toward enhancing organizational innovation. Design/methodology/approach: We undertook a scoping study to determine if and how SFD research and practice aligns with five established themes of design thinking practice. Findings: Design thinking indicators are present across the breadth of SFD research. A total of 14 SFD articles display total thematic alignment with design thinking practice, particularly in regard to five key indicators of such alignment: (a) deep user understanding, (b) diversity of perspectives, (c) testing for user feedback, (d) futuristic thinking, and (e) bias toward action. Practical implications: Five key indicators represent logical points of entry for the employment of design thinking in SFD research and practice. Research contribution: Design thinking has become popular in the broad field of management, but this is the first study of the concept in the sport management domain
The induced metric on the boundary of the convex hull of a quasicircle in hyperbolic and anti-de Sitter geometry
Celebrated work of Alexandrov and Pogorelov determines exactly which metrics on the sphere are induced on the boundary of a compact convex subset of hyperbolic three-space. As a step toward a generalization for unbounded convex subsets, we consider convex regions of hyperbolic three-space bounded by two properly embedded disks which meet at infinity along a Jordan curve in the ideal boundary. In this setting, it is natural to augment the notion of induced metric on the boundary of the convex set to include a gluing map at infinity which records how the asymptotic geometry of the two surfaces compares near points of the limiting Jordan curve. Restricting further to the case in which the induced metrics on the two bounding surfaces have constant curvature K 2 Ć 1; 0/ and the Jordan curve at infinity is a quasicircle, the gluing map is naturally a quasisymmetric homeomorphism of the circle. The main result is that for each value of K, every quasisymmetric map is achieved as the gluing map at infinity along some quasicircle. We also prove analogous results in the setting of three-dimensional anti-de Sitter geometry. Our results may be viewed as universal versions of the conjectures of Thurston and Mess about prescribing the induced metric on the boundary of the convex core of quasifuchsian hyperbolic manifolds and globally hyperbolic anti-de Sitter spacetimes
Quasicircles and width of Jordan curves in CP1
We study a notion of âwidthâ for Jordan curves in (Formula presented.), paying special attention to the class of quasicircles. The width of a Jordan curve is defined in terms of the geometry of its convex hull in hyperbolic three-space. A similar invariant in the setting of anti-de Sitter geometry was used by BonsanteâSchlenker to characterize quasicircles among a larger class of Jordan curves in the boundary of anti de Sitter space. In contrast to the AdS setting, we show that there are Jordan curves of bounded width which fail to be quasicircles. However, we show that Jordan curves with small width are quasicircles
Physiological stress and post-release mortality of white marlin (Kajikia albida) caught in the United States recreational fishery
White marlin, a highly migratory pelagic marine fish, support important commercial and recreational fisheries throughout their range in the tropical and subtropical Atlantic Ocean. More than 10 000 individuals can be caught annually in the United States recreational fishery, of which the vast majority are captured on circle hooks and released alive. The probability of post-release mortality of white marlin released from circle hooks has been documented to b
New Luttinger liquid physics from photoemission on LiMoO
Temperature dependent high resolution photoemission spectra of quasi-1
dimensional LiMoO evince a strong renormalization of its
Luttinger liquid density-of-states anomalous exponent. We trace this new effect
to interacting charge neutral critical modes that emerge naturally from the
two-band nature of the material. LiMoO is shown thereby to
be a paradigm material that is capable of revealing new Luttinger physics.Comment: 4 pages, 3 figures. Accepted for publication by Phys. Rev. Let
Distributed utterances
I propose an apparatus for handling intrasentential change in context. The standard approach has problems with sentences with multiple occurrences of the same demonstrative or indexical. My proposal involves the idea that contexts can be complex. Complex contexts are built out of (âsimpleâ) Kaplanian contexts by ordered n-tupling. With these we can revise the clauses of Kaplanâs Logic of Demonstratives so that each part of a sentence is taken in a different component of a complex context.
I consider other applications of the framework: to agentially distributed utterances (ones made partly by one speaker and partly by another); to an account of scare-quoting; and to an account of a binding-like phenomenon that avoids what Kit Fine calls âthe antinomy of the variable.
Luttinger liquid ARPES spectra from samples of LiMoO grown by the temperature gradient flux technique
Angle resolved photoemission spectroscopy line shapes measured for
quasi-one-dimensional LiMoO samples grown by a temperature
gradient flux technique are found to show Luttinger liquid behavior, consistent
with all previous data by us and other workers obtained from samples grown by
the electrolyte reduction technique. This result eliminates the sample growth
method as a possible origin of considerable differences in photoemission data
reported in previous studies of LiMoO.Comment: Some text adde
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